Liquid crystal parallax barrier with strip-shaped and step-shaped electrodes and application thereof

ABSTRACT

Disclosed herein is a parallax barrier including a first substrate, a second substrate and a liquid crystal layer disposed between the first and the second substrates. A plurality of first strip electrodes and a plurality of second strip electrodes are arranged on the first substrate, whereas a plurality of third electrodes and a plurality of fourth electrodes are arranged on the second substrate. Each of the third electrodes has a step-shaped first portion and each of the fourth electrodes has a step-shaped second portion.

RELATED APPLICATIONS

This application claims priority to Taiwan application No. 099123523,filed Jul. 16, 2010, entitled “PARALLAX BARRIER AND APPLICATIONTHEREOF”, the entirety of which is incorporated herein by reference.

BACKGROUND

1. Field of Invention

The present invention relates generally to parallax devices and methods.More particularly, the present invention relates to parallax devices andmethods capable of rendering autostereoscopic images in two modes.

2. Description of Related Art

Generally, three-dimensional (3D) displays may be categorized intostereoscopic displays and autostereoscopic displays (also referred to asnaked-eye type 3D displays). In stereoscopic technology, users have towear viewing aids, such as shutter glasses, so that the left and righteyes of a user may receive different images respectively, and thereby,the user may perceive a 3D image. In autostereoscopic technology, aspecially designed optical element, such as a parallax barrier, isemployed so as to allow the display device to provide different imagesto the left and right eyes of a user respectively so that the user mayperceive a 3D image with naked eyes.

FIG. 1A is a schematic diagram illustrating the operation principle ofconventional autostereoscopic displays. As shown in FIG. 1A, theautostereoscopic display comprises a display panel 100 and a parallaxbarrier 110 disposed above the display face of the display panel 100.

The display panel 100 comprises at least two substrates 102 and 104, anda liquid crystal layer 106 sandwiched therebetween. In addition, thesubstrate 102 has a pixel array (not shown) consisting of a plurality ofpixels disposed thereon, wherein each pixel corresponds to at least oneliquid crystal cell (such as, 106 a, 106 b) of the liquid crystal layer106.

The parallax barrier 110 comprises: two substrates 116 and 120 opposingeach other; twisted nematic cells (TN cells) 112 and 114 disposedbetween the substrates 116 and 120; two sets of strip electrodes 122 and124 disposed on a surface of the substrate 116; and a surface electrode118 substantially cover the whole surface of the substrate 120. As canbe appreciated by persons with ordinary skill in the art, suchautostereoscopic display may further comprises at least one polarizer(not shown for the sake of brevity); for example, a polarizer may bedisposed below the display panel 100, between the display panel 100 andthe parallax barrier 110, or above the parallax barrier 110. The stripelectrodes 122 and 124 are arranged alternately on the substrate 116,and a strip-shaped parallax structure may be formed by respectivelycontrolling the voltage applied on these electrodes 122 and 124. Forexample, when the electrode 118 and strip electrode set 122 areconnected to ground voltage, whereas another strip electrode set 124 isconnected to a high voltage, the TN cells 112 corresponding to theground electrode set 122 are not driven; whereas TN cells 114corresponding to the strip electrode set 124 (electrically connected tothe high voltage) are drives. As such, when the image (light) renderedby display panel 100 passes through the parallax barrier 110, lightcannot pass through the driven TN cells 114, and can merely pass throughthe non-driven TN cells 112; therefore, the image rendered by thedisplay panel 100 would be transformed into an image with a parallaxbarrier pattern (referred to as a “parallax image” hereinbelow) that iscapable of providing a left-eye image (such as the image from the pixelscorresponding to liquid crystal cells 106 b) and a right-eye image (suchas the image from the pixels corresponding to liquid crystal cells 106a) respectively to a user's left and right eyes, and the user's brain,upon receiving the signals of the left- and right-eye images, mayperceive a three-dimensional image.

Nowadays, many display devices can rotate with respect to a base or abody of an electronic device and provide images under differentviewing/operating modes. For example, a display is under a landscapemode when the display is horizontally oriented (that is, the long sideof the display is oriented to be horizontal); whereas a display is undera portrait mode when the display is vertically oriented (that is, thelong side of the display is oriented to be vertical). However, theconventional parallax barrier as described in FIG. 1A is capable ofrendering the parallax image merely in a single mode. For example, asshown in FIG. 1B, the display can only provide a three-dimensional imageunder the portrait mode when the strip electrode sets 152 and 154 of theparallax barrier 150 are disposed parallel to the long sides of thedisplay device. More specifically, in this case, the image rendered bypixels 162 a and 162 b of the display panel 160 may pass through the TNcells (not shown) corresponding to the electrodes 152 that are connectedto electrical ground, thereby providing a left-eye image (such as, animage corresponding to the image from pixels 160 b) and a right-eyeimage (such as, an image corresponding to the image from pixels 160 a)respectively to the user's left and right eyes, so that the user's brainmay perceive a three-dimensional image.

Considerable problems are faced in designing displays that can renderthree-dimensional image under both the landscape mode and the portraitmode. For example, users have to change their viewing distances underdifferent modes in order to perceive high-quality three-dimensionalimages. Briefly, the viewing distance is the distance between the user'seyes and the display screen (such as “D” illustrated in FIG. 1A).Generally, the viewing distance is in direct proportion to the eyeseparation as well as the distance between the parallax barrier and thepixel array. Besides, the viewing distance is in reverse proportion tothe refractive index of the substrate (such as a glass substrate) aswell as the pixel pitch. Accordingly, if the display is switched fromthe portrait mode to the landscape mode, the pixel pitches under thesetwo modes are different which in turns result in the change of theviewing distance.

Moreover, the parallax barrier employs liquid crystal cells to form thelight-shielding structure. Thus, the display, in conjunction with theliquid crystal cells of the parallax barrier, would be rotated if theuser wishes to switch between the viewing modes. In this case, theliquid crystal cells in the proximity of the peripheral of theelectrodes may not be rotated completely, or the distribution thereofmay be uneven. As such, the user may suffer from chromatic aberration(or the color difference) due to the difference of the viewing angles.

Problems such as viewing distance or chromatic aberration may adverselyaffect the viewing experience of the user and the display quality of thethree-dimensional image. In view of the foregoing, there exists a needin the art for providing a novel parallax barrier and method for formingthree-dimensional images so as to provide users with enhanced viewingexperiences.

SUMMARY

The following presents a simplified summary of the disclosure in orderto provide a basic understanding to the reader. This summary is not anextensive overview of the disclosure and it does not identifykey/critical elements of the present invention or delineate the scope ofthe present invention. Its sole purpose is to present some conceptsdisclosed herein in a simplified form as a prelude to the more detaileddescription that is presented later.

In one aspect, the present invention is directed to a parallax barrier.The three-dimensional image rendered by the present parallax barrier isless likely to suffer from the chromatic aberration result from theviewing angle. Also, the viewing distances under different viewing modesmay be kept similar by using the present parallax barrier.

According to one embodiment of the present invention, the presentparallax barrier comprises a first substrate, a second substrate, and aliquid crystal layer disposed between the first substrate and the secondsubstrate. The first substrate has a plurality of first electrodes and aplurality of second electrodes disposed thereon. The first electrodesare strip-shaped and electrically connected to one another, and aredisposed on the first substrate along a first direction. The secondelectrodes are also strip-shaped and electrically connected to oneanother, and are disposed on the first substrate along the firstdirection, wherein the first electrodes and the second electrodes arearranged alternately. The second substrate has a plurality of thirdelectrodes and a plurality of forth electrodes disposed thereon. Thethird electrodes are electrically connected to one another and disposedon the second substrate along a second direction, wherein each of thethird electrodes comprises a step-shaped first portion. The forthelectrodes are also are electrically connected to one another anddisposed on the second substrate along the second direction, whereineach of the forth electrodes comprises a step-shaped second portion.

In another aspect, the present invention is directed to a displaydevice. The three-dimensional image rendered by the present displaydevice is less likely to suffer from the chromatic aberration resultfrom the viewing angle. Also, the viewing distances under differentviewing modes may be kept similar by using the present display device.

According to one embodiment of the present invention, the display devicecomprises a display panel and a parallax barrier. The display panel maycomprise a plurality of pixels that are arranged into a pixel arrayalong a first direction and a second direction. Each of the pixels has awidth of Wp in the first direction and a height of Hp in the seconddirection. More specifically, each of the pixels may comprise threesub-pixels, and each of the sub-pixels has a width of (Wp/3) in thefirst direction. The parallax barrier is disposed at a display face ofthe display panel, and the parallax barrier comprises a first substrate,a second substrate, and a liquid crystal layer disposed between thefirst substrate and the second substrate. The first substrate has aplurality of first electrodes and a plurality of second electrodesdisposed thereon. The first electrodes are strip-shaped and electricallyconnected to one another, and are disposed on the first substrate alonga first direction. The second electrodes are also strip-shaped andelectrically connected to one another, and are disposed on the firstsubstrate along the first direction, wherein the first electrodes andthe second electrodes are arranged alternately. The second substrate hasa plurality of third electrodes and a plurality of forth electrodesdisposed thereon. The third electrodes are electrically connected to oneanother and disposed on the second substrate along a second direction,wherein each of the third electrodes comprises a step-shaped firstportion. The forth electrodes are also are electrically connected to oneanother and disposed on the second substrate along the second direction,wherein each of the forth electrodes comprises a step-shaped secondportion. More specifically, the first portion of each third electrodemay comprise three first segments arranged along the second direction asstep-shaped, and a step difference between any two adjacent firstsegments is (Wp/3) or (2 Wp/3). Similarly, the second portion of eachforth electrode may comprise three second segments arranged along thesecond direction as step-shaped, and a step difference between any twoadjacent second segments is (Wp/3) or (2 Wp/3).

In yet another aspect, the present invention is directed to a displaydevice. The three-dimensional image rendered by the present displaydevice is less likely to suffer from the chromatic aberration resultfrom the viewing angle. Also, the viewing distances under differentviewing modes may be kept similar by using the present display device.

According to one embodiment of the present invention, the display devicecomprises a display panel and a parallax barrier. The display panel isoperable to render a two-dimensional image; whereas the parallax barrieris any parallax barriers according to the previous aspects andembodiments of the present invention. As such, the present parallaxbarrier is operable to transform the two-dimensional image rendered bythe display panel into a parallax image, and the parallax image mayprovide a left-eye image and right-eye image to user's left and righteyes respectively, so that the user may perceive a three-dimensionalimage.

In still another aspect, the present invention is directed to a methodfor forming an autostereoscopic image.

According to one embodiment of the present invention, the methodcomprises the steps as follows. A two-dimensional image is rendered byusing a display element. A parallax barrier according to the previousaspects and embodiments of the present invention is operated totransform the two-dimensional image into a parallax image. The parallaximage is capable of providing a left-eye image and a right-eye image toa user's left and right eyes respectively so that the user perceives athree-dimensional image.

Many of the attendant features will be more readily appreciated as thesame becomes better understood by reference to the following detaileddescription considered in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present description will be better understood from the followingdetailed description read in light of the accompanying drawings,wherein:

FIG. 1A is a schematic diagram illustrating the operating principles ofa conventional autostereoscopic display;

FIG. 1B is a schematic diagram illustrating a conventionalautostereoscopic display that can render a parallax image under a singleviewing mode;

FIG. 2 is a schematic cross-section diagram illustrating a parallaxbarrier according to one embodiment of the present invention;

FIG. 3A is a schematic diagram illustrating the electrode arrangement onthe first substrate of the parallax barrier as shown in FIG. 2;

FIG. 3B is a schematic diagram illustrating the electrode arrangement onthe second substrate of the parallax barrier as shown in FIG. 2;

FIG. 4A is an exemplary electrodes layout according to one embodiment ofthe present invention;

FIG. 4B is an exemplary electrodes layout according to anotherembodiment of the present invention;

FIG. 4C is an exemplary electrodes layout according to yet anotherembodiment of the present invention;

FIG. 5A is a schematic cross-section diagram illustrating a displaydevice according to one embodiment of the present invention;

FIG. 5B is a schematic diagram illustrating the electrode arrangementson the first substrate and the second substrate of the parallax barrierof the display device as shown in FIG. 5A under the first mode;

FIG. 5C is a schematic diagram illustrating the pixel arrangement of thedisplay panel of the display device as shown in FIG. 5A under the firstmode;

FIG. 5D is a schematic diagram illustrating the parallax structureformed, under the first mode, by the electrode arrangements of FIG. 5Band pixel arrangement of FIG. 5C;

FIG. 6A is a schematic diagram illustrating the electrode arrangementson the first substrate and the second substrate of the parallax barrierof the display device as shown in FIG. 5A under the second mode;

FIG. 6B is a schematic diagram illustrating the pixel arrangement of thedisplay panel of the display device as shown in FIG. 5A under the secondmode;

FIG. 6C is a schematic diagram illustrating the parallax structureformed, under the second mode, by the electrode arrangements of FIG. 6Aand pixel arrangement of FIG. 6B;

FIG. 6D is a schematic diagram illustrating the principles for forming athree-dimensional image under the second mode according to the displaydevice as shown in FIGS. 6A to 6C;

FIGS. 7A to 7E are schematic diagrams respectively illustratingexemplary arrangements of various third electrodes according tovarieties of embodiments of the present invention; and

FIG. 8 is a flow chart illustrating the method for formingautostereoscopic images according to one embodiment of the presentinvention.

Like reference numerals are used to designate like parts in theaccompanying drawings.

DETAILED DESCRIPTION

The detailed description provided below in connection with the appendeddrawings is intended as a description of the present examples and is notintended to represent the only forms in which the present example may beconstructed or utilized. The description sets forth the functions of theexample and the sequence of steps for constructing and operating theexample. However, the same or equivalent functions and sequences may beaccomplished by different examples.

One problem faced in rendering three-dimensional images is the chromaticaberration caused by the viewing angles of the user. In addition, inconventional display device, the viewing distances under the portraitmode and the landscape mode are quite different. Aiming at solving atleast the problems described above, in one aspect, the present inventionis directed to a parallax barrier. Reference is now made to FIG. 2 andFIGS. 3A and 3B, which are illustrations of structures of the presentparallax barrier.

FIG. 2 is a schematic diagram illustrating the parallax barrieraccording to one embodiment of the present invention.

As shown in FIG. 2, the parallax barrier 200 comprises a first substrate210, a second substrate 220, a plurality of first electrodes 212 and aplurality of second electrodes 216 disposed on the first substrate 210,a plurality of third electrodes 222 and a plurality of forth electrodes226 disposed on the second substrate 220, and a liquid crystal layer 230disposed between the first substrate 210 and the second substrate 220.

In the present embodiment, the liquid crystal layer 230 consists oftwisted nematic (TN) cells. In considering generally the conditions forcarrying out this invention, the first substrate 210 and/or the secondsubstrate 220 can be any suitable substrate; for example, the firstsubstrate 210 and the second substrate 220 can be glass substrates.However, the present invention is not limited thereto.

FIG. 3A and FIG. 3B are respectively illustrations of the electrodearrangements on the first substrate 210 and the second substrate 220 ofthe parallax barrier 200 as shown in FIG. 2. As shown in FIG. 3A, thefirst substrate 210 has a plurality of first electrodes 212 and aplurality of second electrodes 216 disposed thereon. The firstelectrodes 212 are disposed on a surface of the first substrate 210 andextend along a first direction (such as, direction X illustrated in FIG.3A). The first electrodes 212 are strip-shaped and electricallyconnected to one another, such as, by means of the first connecting part214. Similarly, the second electrodes 216 are also disposed on thesurface of the first substrate 210 and extend along the first directionX. The second electrodes 216 are strip-shaped and electrically connectedto one another, such as, by means of the second connecting part 218. Thefirst electrodes 212 and the second electrodes 216 are arrangedalternately. Besides, the first connecting part 214 and the secondconnecting part 218 are disposed on the two opposite sides in the Xdirection on the first substrate 210.

Next, as shown in FIG. 3B, the second substrate 220 has a plurality ofthird electrodes 222 and a plurality of forth electrodes 226 disposedthereon. The third electrodes 222 are disposed on a surface of thesecond substrate 220 and extend along a second direction (such as,direction Y illustrated in FIG. 3B) that is perpendicular to the firstdirection X. Each of the third electrodes 222 comprises a first portionbeing step-shaped (as illustrated in FIG. 3B). Moreover, the thirdelectrodes 222 are electrically connected to one another by the thirdconnecting part 224. The forth electrodes 226 are also disposed on thesurface of the second substrate 220 and extend along the seconddirection. Each of the forth electrodes 226 comprises a second portionbeing step-shaped (as illustrated in FIG. 3B). Similarly, the forthelectrodes 226 are electrically connected to one another by the forthconnecting part 228. The third electrodes 222 and the forth electrodes226 are arranged alternately. Besides, the third connecting part 224 andthe forth connecting part 228 are disposed on the two opposite sides inthe Y direction on the second substrate 220.

Although exemplary arrangements of the first, second, third and forthelectrodes are illustrated in FIG. 3A and FIG. 3B, the present inventionis not limited thereto. Rather, as persons with ordinary skill in theart would recognize, there are numerous other arrangements that would bewell within the scope of the present invention.

For example, in one embodiment, the phrase “the first electrodes 212 andthe second electrodes 216 are arranged alternately” means that one firstelectrode 212 is disposed between two adjacent second electrodes 216;however, in alternative embodiments, multiple, such as two, three ormore, first electrodes 212 may be disposed in two adjacent secondelectrodes 216. Of course, in another embodiment, one second electrode216 is disposed between two adjacent first electrodes 212; inalternative embodiments, multiple, such as two, three or more, secondelectrodes 216 may be disposed between two adjacent first electrodes212.

Similarly, in one embodiment, the phrase “the third electrodes 222 andthe forth electrodes 226 are arranged alternately” means that one thirdelectrode 222 is disposed between two adjacent forth electrodes 226; inalternative embodiments, multiple, such as two, three or more, thirdelectrodes 222 are disposed between two adjacent forth electrodes 226.In another embodiment, one forth electrode 226 is disposed between twoadjacent third electrodes 222; in alternative embodiments, multiple,such as two, three or more, forth electrodes 226 are disposed betweentwo adjacent third electrodes 222.

In theory, the gap between any two adjacent electrodes should be asnarrow as possible so that the parallax barrier 200 may exhibit a betterparallax effect. Therefore, according to optional embodiments of thepresent invention, the gap between the adjacent first electrode 212 andsecond electrode 216 is smaller than or equal to 6 μm. Similarly,optional embodiments of the present invention, the gap between theadjacent third electrode 222 and forth electrode 226 is smaller than orequal to 6 μm.

According to various embodiments of the present invention, the firstelectrodes 212, the second electrodes 216, the third electrodes 222, andthe forth electrodes 226 may be made of a transparent conducivematerial, respectively. Illustrative examples of the transparentconducive material, include, but are not limited to: indium tin oxide(ITO), indium zinc oxide (IZO), fluorine doped tin oxide (FTO), aluminumzinc oxide (AZO), gallium zinc oxide (GZO), zinc oxide (ZnO), tindioxide (SnO₂) and the combinations of the abovementioned materials. Asan example, rather than a limitation, the electrodes may be transparentconductive layers made of ITO. In one preferred embodiment, the materialof the first, second, third and the forth connecting parts 214, 218,224, and 228 can be the same as that of the first, second, third andforth electrodes 212, 216, 222, and 226.

In one alternative embodiment, any one set or any one electrode of thefirst, second, third and forth electrodes 212, 216, 222, and 226 mayoptionally comprises a plurality of transparent conductive patterns andat least one bridging pattern. Examples of such electrode design areillustrated in FIG. 4A and FIG. 4B.

FIG. 4A and FIG. 4B are illustrations of two exemplary electrodeslayouts according to embodiments of the present invention. For the sakeof brevity, only the layouts of the first electrodes 212, the secondelectrodes 216, the third electrodes 222, and the forth electrodes 226are illustrated, whereas the other portions (such as those illustratedin FIG. 2) of the parallax barrier are omitted.

As shown in FIG. 4A, each of the first electrodes 212 may comprise aplurality of transparent conductive pattern 242 and at least one opaquebridging pattern 244. More specifically, the transparent conductivepattern 242 are separated from each other, and each bridging pattern 244bridges between two adjacent transparent conductive patterns 242, sothat the adjacent transparent conductive patterns 242 are electricallyconnected to each other. Besides, the bridging pattern 244 is disposedabove the gap between the adjacent third electrodes 222 and forthelectrodes 226.

As described hereinabove, a plurality of first electrodes 212 aredisposed on the first substrate 210, and the electrode design where thetransparent conductive patterns are bridged (connected) by bridgingpattern(s) can be applied in all or a portion of the first electrodes212. Besides, although the first electrodes 212 are taken as an examplein FIG. 4A to illustrate such electrode design, the present invention isnot limited thereto. Rather, such electrode design may be applied to thesecond electrodes 216, or alternatively, to both the first electrodes212 and the second electrodes 216.

An electrode design of the third electrodes 222 is illustrated in FIG.4B. As shown in FIG. 4B, each of the third electrodes 222 may comprise aplurality of transparent conductive pattern 252 and at least one opaquebridging pattern 254. More specifically, the transparent conductivepattern 252 are separated from each other, and each opaque bridgingpattern 254 bridges between two adjacent transparent conductive patterns252, so that the adjacent transparent conductive patterns 252 areelectrically connected to each other. Besides, the bridging pattern 254is disposed above the gap between the adjacent first electrodes 212 andsecond electrodes 216.

As described hereinabove, a plurality of third electrodes 222 aredisposed on the second substrate 220, and the electrode design where thetransparent conductive patterns are bridged (connected) by bridgingpattern(s) can be applied in all or a portion of the third electrodes222. Besides, it should be noticed that the third electrodes 222comprises a plurality of non-rectangular segments each consisting of atransparent conductive pattern 252 and an opaque bridging pattern 254,whereas the forth electrodes 226 comprises a plurality of rectangularsegments, as shown in FIG. 4B.

Although the third electrodes 222 are taken as an example in FIG. 4B toillustrate such electrode design, the present invention is not limitedthereto. Rather, such electrode design may be applied to the forthelectrodes 226, or alternatively, to both the third electrodes 222 andthe forth electrodes 226. In one optional embodiment, the electrodesdesigns illustrated in FIG. 4A and FIG. 4B can be applied to the firstelectrodes 212 and second electrodes 216, and the third electrodes 222and the forth electrodes 226, respectively.

In one optional embodiment, the opaque bridging patterns 244 and 254 maybe made of an opaque metal material, respectively. As an example, ratherthan a limitation, metal materials suitable for use herein can be anyone of the followings: silver, gold, copper, palladium, chromium,platinum, molybdenum, titanium, tantalum, tungsten, aluminum, iron,cobalt, zinc, tin, nickel, and an alloy or a combination of theforegoing materials.

In manufacturing the electrodes as shown in FIG. 4A or FIG. 4B, aplurality of transparent conductive patterns that are separated fromeach other and bridging pattern(s) made of an opaque metal material areformed separately.

Alternatively, in another manufacturing process, continuous transparentconductive electrodes are formed first, and then, an opaque metal layeris formed on the specified positions to serve as the bridging patterns.For example, as illustrated in the parallax barrier of FIG. 4C, aplurality of first electrodes 212 and a plurality of second electrodes(not shown) are formed on a surface of the first substrate 210, whereineach of the first electrodes 212 is a continuous transparent conductiveelectrode, and opaque bridging patterns 264 are formed on a surface ofthe first electrode 212. As shown in FIG. 4C, each of the opaquebridging patterns 264 is disposed at the overlap between the firstelectrode 212 and a gap between the two adjacent third electrode 222 andforth electrode 226.

In one optional embodiment, a black matrix layer (not shown) may bedisposed on the first substrate 210 or the second substrate 220, so asto shield the gaps between the third electrodes 222 and the forthelectrodes 226 on the second substrate 220. Alternatively, in anotheroptional embodiment, a black matrix layer (not shown) may be disposed onthe first substrate 210 or the second substrate 220, so as to shield thegaps between the first electrodes 212 and the second electrodes 216 onthe first substrate 210. Alternatively, in still another optionalembodiment, a black matrix layer may be disposed on the first substrate210 or the second substrate 220, so as to shield the gaps between thefirst electrodes 212 and the second electrodes 216 and the gaps betweenthe third electrodes 222 and the forth electrodes 226 at the same time.

In one optional embodiment, the third electrodes 222 may furthercomprise a step-shaped third portion (not shown) in addition to thefirst portion. Alternatively, the forth electrodes 226 may furthercomprise a step-shaped forth portion (not shown) in addition to thesecond portion.

In another aspect, the present invention is directed to a displaydevice. The three-dimensional image rendered by the present displaydevice is less likely to suffer from the chromatic aberration resultfrom the viewing angle. Also, the viewing distances under differentviewing modes may be kept similar by using the present display device.

According to one embodiment of the present invention, the display devicecomprises a display panel and a parallax barrier according to theabove-mentioned aspect/embodiments of present invention (such as,parallax barrier 200). The parallax barrier is disposed at a side of thedisplay panel (such as, a display face or a light-incident face of adisplay panel). Briefly, a display panel comprises a plurality ofpixels, and the arrangements of the electrodes of the parallax barriercan be designed based on the arrangement of these pixels.

In implantation, the display panel may comprise any display panelcapable of rendering a two-dimensional image. Illustrative examples ofsuch display panel include, but are not limited to: a liquid crystaldisplay unit, an electroluminescent display unit and an electrophoreticdisplay unit.

A display device 570 according to one embodiment of the presentinvention is depicted in FIG. 5A. The display device 570 comprises adisplay panel 550 and a parallax barrier 500. Take FIG. 5A as anexample, the display panel 550 is a liquid crystal display unit whichcomprises a pair of substrates 572 and 574 and a liquid crystal layer576 sandwiched therebetween. The liquid crystal layer 576 comprises aplurality of liquid crystal cells, and each of the liquid crystal cellsis corresponding to the pixel arrangement (that is the pixel arrangement560 as illustrated in FIG. 5C) disposed on the substrate 576. It shouldbe noted that, for the sake of simplicity and clarity of the drawing,the gap between the first electrodes 512 and the second electrodes 516,as well as the gap between the third electrodes 522 and the forthelectrodes 526, are not shown in FIG. 5A.

As can be appreciated by persons with ordinary skill in the art, thedisplay panel 550 may further comprise a polarizer (not shown). Thepolarizer may be disposed on a surface of the substrate 572 and/or asurface of the substrate 574. In addition, the display panel 550 mayfurther comprise a light source, such as a backlight module (not shown)disposed at a light-incident face of the display panel 550 (such as,under the substrate 572). Moreover, the display panel 550 may comprise acolor filter (not shown) so that the display panel 550 may render acolor two-dimensional image. The materials and constructions formanufacturing the liquid crystal display unit, including that of thepolarizer, color filter and/or backlight module, are well known to thosewith ordinary skill in the art, and hence, are not discussed in detailedherein.

Besides, although both of the parallax barrier 500 and the display panel550 are depicted to have two substrates in FIG. 5A, it is possible toomit one of the two substrates in optional embodiments. For example, thefirst substrate 506 of the parallax barrier 500 may be omitted, and thesubstrate 574 can be shared by the parallax barrier 500 and the displaypanel 550. Alternatively, the second substrate 574 of the display panel550 may be omitted, and the substrate 506 can be shared by the parallaxbarrier 500 and the display panel 550.

The structures and operating principles of the display device 570 underdifferent viewing modes are discussed hereinabove in connection withFIGS. 5A to 5D and FIGS. 6A to 6D.

The electrode arrangement 510 of the parallax barrier 500 and pixelarrangement 560 of the display panel 550 under the first mode (forexample, the portrait mode) are depicted in FIG. 5B and FIG. 5Crespectively.

Reference is made to FIG. 5A and FIG. 5B. As shown in the figures, theparallax barrier 500 is similar to the parallax barrier 200 andcomprises a first substrate 506, a second substrate 508, a liquidcrystal layer 505 disposed between the first substrate 506 and thesecond substrate 508, a plurality of first electrodes 512 and aplurality of second electrodes 516 disposed on the first substrate 506,and a plurality of third electrodes 522 and a plurality of forthelectrodes 526 disposed on the second substrate 508.

For the sake of simplicity and clarity, only the layouts of theelectrodes on the first substrate 506 and the second substrate 508 aredepicted in FIG. 5B. The electrodes layout on the first substrate asshown in FIG. 5B is similar to that as depicted in FIG. 3A, wherein theplurality of first electrodes 512 and the plurality of second electrodes516 are disposed on the first substrate (not shown in FIG. 5B). Thefirst electrodes 512 are disposed on a surface of the first substrateand extend along a first direction X, and the first electrodes 512 arestrip-shaped and electrically connected to one another. Similarly, thesecond electrodes 516 are also disposed on the first substrate andextend along the first direction X, and the second electrodes 516 arestrip-shaped and electrically connected to one another. The firstelectrodes 512 and the second electrodes 516 are arranged alternately.

As shown in FIG. 5C, the display panel 550 may comprise a plurality ofpixels 552 that are arranged into a pixel array along the firstdirection X and the second direction Y. Each pixel 552 has a width of Wpin the first direction X and a height of Hp in the second direction Y.More specifically, each pixel 552 may comprise three sub-pixels 554, andeach sub-pixel 554 has a width of (Wp/3) in the first direction X and aheight of Hp in the second direction Y.

Returning back to FIG. 5B, the electrodes layout on the second substrateas shown in FIG. 5B is similar to that as depicted in FIG. 3B, wherein aplurality of third electrodes 522 and a plurality of forth electrodes526 are disposed on the second substrate (not shown in FIG. 5B) of theparallax barrier 500. The third electrodes 522 are disposed on a surfaceof the second substrate and extend along a second direction Y that isperpendicular to the first direction X. The third electrodes 522 areelectrically connected to one another, and each of the third electrodes522 comprises a step-shaped first portion 530. The forth electrodes 526are also disposed on the second substrate and extend along the seconddirection Y. Similarly, the forth electrodes 526 are electricallyconnected to one another, and each of the forth electrodes 526 comprisesa step-shaped second portion 540. The third electrodes 522 and the forthelectrodes 526 are arranged alternately.

More specifically, the first portion 530 of each third electrode 522 maycomprise three first segments 532 a, 532 b, and 532 c disposed along thesecond direction Y. The first segments 532 a, 532 b, and 532 c arearranged in step-shape; wherein a step difference D₁ between any twoadjacent first segments (such as 532 a and 532 b) is (Wp/3) or (2 Wp/3).In other words, the step difference D₁ between any two adjacent firstsegments in the X direction is substantially the same as the width ofone or two sub-pixels in the first direction X.

Similarly, the second portion 540 of each forth electrode 526 maycomprise three second segments 542 a, 542 b, and 542 c disposed alongthe second direction Y. The second segments 542 a, 542 b, and 542 c arearranged in step-shape; wherein a step difference D₂ between any twoadjacent second segments (such as 542 b and 542 c) is (Wp/3) or (2Wp/3). In other words, the step difference D₂ between any two adjacentsecond segments in the X direction is substantially the same as thewidth of one or two sub-pixels in the first direction X.

As can be appreciated by persons with ordinary skill in the art, each ofthe first electrodes 512, second electrodes 516, third electrodes 522,and forth electrodes 526 described herein may be similar to therespective first electrodes 212, second electrodes 216, third electrodes222, and forth electrodes 226 in structure and design. Hence, thedescriptions provided hereinabove in connection with the first, second,third and forth electrodes 212, 216, 222 and 226 are applicable to thefirst, second, third and forth electrodes 512, 516, 522 and 526described in the present embodiment.

For example, the first electrodes 512 and the second electrodes 516 ofthe parallax barrier 500 may have a gap therebetween. Alternatively, thethird electrodes 522 and the forth electrodes 526 may have a gaptherebetween.

Besides, each of the first, second, third and forth electrodes 512, 516,522 and 526 of the parallax barrier 500 may be made of a transparentconductive layer, respectively. Alternatively, the first, second, thirdand forth electrodes 512, 516, 522 and 526 may each have a structuredescribed hereinabove in connection with FIG. 4A, FIG. 4B or FIG. 4C.More specifically, in one optional embodiment, each of the electrodesmay have a plurality of transparent conductive patterns separated fromeach other and at least one opaque bridging pattern bridging between thetransparent conductive patterns. In an alternative embodiment, each ofthe electrodes may comprise at least one opaque bridging pattern whichis disposed at the overlap between the third electrode and a gap betweenthe adjacent first electrode and second electrode or the overlap betweenthe first electrode and a gap between the adjacent third electrode andforth electrode. Similarly, the opaque bridging pattern may be made of amaterial comprising the opaque metal described hereinabove.

Moreover, the parallax barrier 500 may further comprise a black matrixlayer as described hereinabove. The black matrix layer may be disposedon either of the first substrate 506 and the second substrate 508 so asto shield the gap(s) between the third electrodes 522 and the forthelectrodes 526 on the second substrate 508. Alternatively, the blackmatrix layer may be disposed on either of the first substrate 506 andthe second substrate 508 so as to shield the gap(s) between the firstelectrodes 512 and the second electrodes 516 on the first substrate 506.Still alternatively, in one optional embodiment, the black matrix layermay be disposed on either of the first substrate 506 and the secondsubstrate 508 so as to shield the gap(s) between the first electrodes512 and the second electrodes 516 and the gaps between the thirdelectrodes 522 and the forth electrodes 526 at the same time.

As used in the present specification, each of the first segments 532 a,532 b, and 532 c has a segment height of H₁ in the second direction Yand a segment width of W₁ in the first direction X, as depicted in FIG.5B. Also, each of the second segments 542 a, 542 b, and 542 c has asegment height of H₂ in the second direction Y and a segment width of W₂in the first direction X, as depicted in FIG. 5B.

In one embodiment, the segment width W₁ is less than the width Wp ofeach pixel 552, and the segment width W₂ is also less than the width Wpof each pixel 552. In another embodiment, the segment width W₁ is equalto the width Wp of each pixel 552, and the segment width W₂ is less thanthe width Wp of each pixel 552. In one embodiment, the segment height H₁or H₂ is substantially equal to the height Hp of each pixel 552.

In optional embodiments, the height of each first electrode 512 and eachsecond electrode 516 in the second direction Y is less than the heightHp of each pixel 552.

Reference is now made to FIGS. 5A to 5D, under the first viewing mode;the steps for operating the parallax barrier 500 so that the displaydevice 570 may render an autostereoscopic image are as follows.

A reference voltage (usually a ground voltage) is applied to the secondelectrodes 516, the third electrodes 522, and the forth electrodes 526,while a data voltage (usually a voltage different from the groundvoltage) is applied to the first electrodes 512. In this case, theelectric filed formed by the first electrodes 512 may drive the liquidcrystal cells 505 a (i.e., the cells that are disposed at positionscorresponding to the first electrodes 512), and hence, the light cannotpass through these portions. In contrast, liquid crystal cells 505 bdisposed at the other portions (such as those being disposed atpositions corresponding to the second electrodes 516) are not driven,thereby allowing light to pass therethrough. As such, under the firstmode, a parallax structure 580 (as shown in FIG. 5D) may be formed bythe cooperation of the parallax barrier 500 and the pixel arrangement560 (as shown in FIG. 5C) of the display panel 550. Hence, under thefirst mode, when a two-dimensional image rendered by the display panel550 passes through the parallax barrier 500, the parallax structure 580is able to transform the two-dimensional image into a parallax image.Specifically, the parallax image is an image that comprises a left-eyeimage (rendering by the pixels labeled with “Left” in FIG. 5D) and aright-eye image (rendering by the pixels labeled with “Right” in FIG.5D), and when a user's left and right eyes receive the left-eye imageand right-eye image respectively, the user's brain is able to perceive athree-dimensional image. More specifically, the liquid crystal cells 576a shown in FIG. 5A are corresponding to the right-eye pixels depicted inFIG. 5C, whereas the liquid crystal cells 576 b shown in FIG. 5A arecorresponding to the left-eye pixels depicted in FIG. 5C. As such, theuser's brain may perceive a three-dimensional image as illustrated inFIG. 5A.

Next, reference is made to FIG. 6A and FIG. 6B which are illustrationsof the electrode arrangement 510 of the parallax barrier 500 and thepixel arrangement 560 of the display panel 550 under the second mode(such as, the landscape mode). In fact, the structures depicted in FIG.6A and FIG. 6B are the same as FIG. 5B and FIG. 5C, except that thedrawings are rotated by 90 degrees clockwise.

Under the second viewing mode, the steps for operating the parallaxbarrier 500 so that the display device 570 may render anautostereoscopic image are as follows.

A reference voltage (usually a ground voltage) is applied to the firstelectrodes 512, the second electrodes 516 and the forth electrodes 526,while a data voltage (usually a voltage higher than the ground voltage)is applied to the third electrodes 522. In this case, the electric filedformed by the third electrodes 522 may drive the liquid crystal cells505 c (i.e., the cells that are disposed at positions corresponding tothe second electrodes 522), and hence, the light cannot pass throughthese portions. In contrast, liquid crystal cells 505 d disposed at theother portions (such as those being disposed at positions correspondingto the forth electrodes 526) are not driven, thereby allowing light topass therethrough. As such, under the second mode, a parallax structure590 (as shown in FIG. 6C) may be formed by the cooperation of theparallax barrier 500 and the pixel arrangement 560 (as shown in FIG. 6B)of the display panel 550. Hence, under the second mode, when atwo-dimensional image rendered by the display panel 550 passes throughthe parallax barrier 500, the parallax structure 590 is able totransform the two-dimensional image into a parallax image that iscapable of providing a left-eye image (rendering by the pixels labeledwith “Left” in FIG. 6C) and a right-eye image (rendering by the pixelslabeled with “Right” in FIG. 6C) to a user's left and right eyes,respectively, so that the user's brain is able to perceive athree-dimensional image.

Next, please refer to FIG. 6D which is a schematic illustration of thethree-dimensional image formed by the display device 570 under thesecond mode. For the sake of the simplicity and clarity, the gapsbetween the third electrodes 522 and the forth electrodes 526 are notdepicted in FIG. 6D.

As shown in FIG. 6D, the liquid crystal cells 576 c are corresponding tothe right-eye pixels depicted in FIG. 6C, whereas the liquid crystalcells 576 d are corresponding to the left-eye pixels depicted in FIG.6C. As such, the user's brain may perceive a three-dimensional image asillustrated in FIG. 6D.

As described hereinabove, rotated to switch between the two viewingmodes, the display device should be rotated, and so do the liquidcrystal cells disposed therein. Conventionally, if the liquid crystalcells in the proximity of the peripheral of the electrodes are notrotated completely, or if the distribution of these liquid crystal cellsis uneven, the display device may exhibit severe chromatic aberration.However, the step-shaped electrodes employed in the parallax barrier ofthe present invention (such as parallax barrier 200 or 500) may addresssuch issue properly.

Please refer to FIGS. 6A-6C, in the first direction X, the step D₁between any two adjacent first segments (532 a, 532 b, and 532 c) ofeach third electrode 522 is (Wp/3), and the width of each sub-pixel 554of each pixel 552 is also (Wp/3). Therefore, by tying the presentelectrode arrangement with the present pixel arrangement, the firstsub-pixels in the X direction of the pixel corresponding to each of thethree first segments 532 a, 532 b, and 532 c of the first portion 530 isR, G and B, respectively, as shown in FIG. 6C. In other words, thesub-pixels at the peripheral of the first portion 530 of the thirdelectrodes 522 are not the same kind of sub-pixels. As such, even if theliquid crystal cells in the proximity of the peripheral of theelectrodes are not rotated completely, or if the distribution of theseliquid crystal cells is uneven, the chromatic aberration caused by theviewing angles can be improved, because all of the three kinds ofsub-pixels (R, G, and B) may suffer from the above-identified problem,and the chromatic aberrations caused by each kind of sub-pixels mayoffset one another.

Moreover, the arrangement of the step-shaped electrodes is designedbased on the pixel arrangement in such a way that the pixel pitches ofthe display panel under both the first mode (such as, the portrait mode)and the second mode (such as, the landscape mode) are substantially thesame. Accordingly, when a user switches between different viewing modes,he or she does not have to alter the viewing distance substantially inorder to view clear three-dimensional images.

Although the first segments 532 a, 532 b, and 532 c are depicted to havea step D₁ of (Wp/3), as illustrated in FIG. 5B and FIG. 6A, the presentinvention is not limited to such electrode arrangement. Rather, as willbe apparent to one of ordinary skill in the art after reading thepresent specification, numerous alternative architectures can be used toimplant the electrode arrangement according to the present invention.

For example, some exemplary electrode arrangements are illustrated inFIG. 7A to FIG. 7E, all of which is suitable to use with the pixelarrangement illustrated in FIG. 6B. To facilitate the understanding ofthese drawings and the following discussions, the direction denoted byfull-line arrow X is referred to as the right side, and the directiondenoted by full-line arrow Y is referred to as the lower side. Besides,only the sub-pixels that are corresponding to the third electrodes aredenoted with R, G, or B in the drawings, whereas the other pixels and/orsub-pixels are omitted.

In FIG. 7A, the third electrode 600 comprises two first portions 605 aand 605 b disposed along the Y direction. Each of the first portions 605a and 605 b consists of three first segments 601, 602 and 603. The firstsegment 601 is disposed at the upper side and shifts by a distance of(Wp/3) to the left with respect to the first segment 602; whereas thefirst segment 603 is disposed at the lower side and shifts by a distanceof (Wp/3) to the right with respect to the first segment 602. In thisway, each of the first sub-pixels in the X direction of the pixelcorresponding to each of the first segments 601, 602, and 603 of thefirst portions 605 a and 605 b is R, G and B, respectively. Besides, thefirst segment 601 of the first portion 605 b is disposed at the lowerside and shifts by a distance of (Wp/3) to the right with respect to thefirst segment 603 of the first portion 605 a.

Similarly, the third electrode 610 depicted in FIG. 7B comprises twofirst portions 615 a and 615 b disposed along the Y direction. Each ofthe first portions 615 a and 615 b consists of three first segments 611,612 and 613. The first segment 611 is disposed at the upper side andshifts by a distance of (2 Wp/3) to the left with respect to the firstsegment 612; whereas the first segment 613 is disposed at the lower sideand shifts by a distance of (Wp/3) to the left with respect to the firstsegment 612. In this way, each of the first sub-pixels in the Xdirection of the pixel corresponding to each of the first segments 611,612, and 613 is R, B and G, respectively. Besides, the first segment 611of the first portion 615 b is disposed at the lower side and shifts by adistance of (Wp/3) to the left with respect to the first segment 613 ofthe first portion 615 a.

As shown in both FIG. 7A and FIG. 7B, two first portions are arranged inthe Y direction to form the third electrodes; however, the presentinvention is not limited thereto. Take FIG. 7A as an example, thenumbers of first portion 605 of the third electrode 600 may be altereddepending on the actual pixel arrangement. Also, it is also possible toalter the relative disposition of the first portions depending onsituations and applications.

Moreover, the present invention is not limited to arranging multiplefirst portions in the Y direction to form the third electrodes; rather,it is possible to use two or more different step-shaped portions to formthe third electrodes.

For example, as shown in FIG. 7C, the third electrode 620 comprises afirst portion 625 and a third portion 629 disposed along the Ydirection. More specifically, the first portion 625 comprises threefirst segments 621, 622 and 623, wherein the first segment 621 isdisposed at the upper side and shifts by a distance of (2 Wp/3) to theleft with respect to the first segment 622, whereas the first segment623 is disposed at the lower side and shifts by a distance of (2 Wp/3)to the right with respect to the first segment 622. In this way, each ofthe first sub-pixels in the X direction of the pixel corresponding toeach of the first segments 621, 622, and 623 is R, B and G,respectively. The third portion 629 mirrors the first portion 625. Assuch, each of the first sub-pixels in the X direction of the pixelcorresponding to each of the third segments 626, 627, and 628 of thethird portion 629 is G, B and R, respectively. In this example, sincethe third portion 629 is a mirror image of the first portion 625, thereis no shift between the third segment 626 of the third portion 629 andthe first segment 623 of the first portion 625.

In the embodiment illustrated in FIG. 7D, the third electrode 630comprises a first portion 635 and a third portion 639 disposed along theY direction. The arrangement of the first segments 631, 632 and 633 ofthe first portion 635 is the same as that of the first portion 605 a asdepicted in FIG. 7A, whereas the arrangement of the third segments 636,637 and 638 is the same as that of the first portion 615 a as depictedin FIG. 7B. In this way, each of the first sub-pixels in the X directionof the pixel corresponding to each of the first segments 631, 632, and633 is R, G and B, respectively, whereas each of the first sub-pixels inthe X direction of the pixel corresponding to each of the third segments636, 637, and 638 is R, B and G, respectively. In the present example,the third segment 636 is disposed at a lower side and shifts by adistance of (2 Wp/3) to the left with respect to the first segment 633of the first portion 635.

In FIG. 7E, the third electrode 640 comprises two first portions 645 aand 645 b disposed along the Y direction. The arrangements of the firstportions 645 a and 645 b are the same as that of the first portions 615a and 615 b as depicted in FIG. 7B, and hence, the reference numerals ofthe first segments of the first portions 615 a and 615 b are appliedherein. The third electrode 640 of

FIG. 7E differs from the third electrode 610 of FIG. 7B in that thefirst segment 611 of the first portion 645 b, which is disposed at thelower side, shifts by a distance of (2 Wp/3) to the right with respectto the first segment 613 of the first portion 645 a.

The exemplary electrode arrangements of the third electrodes illustratedin FIG. 7A to FIG. 7E are suitable for use in the parallax barriers 200and/or 500 described hereinabove, so as to implant the presentinvention. Besides, although the examples depicted in FIG. 7A to FIG. 7Eare directed to the arrangement of the third electrodes, those electrodearrangements are equally applicable to the forth electrode, such as theforth electrodes 226 or 526 described hereinabove. Moreover, inpreferred embodiments, the arrangements of the third electrodes and theforth electrodes are complementary to each other.

In yet another aspect, the present invention is directed to a displaydevice, which employs the parallax barrier according to theaspects/embodiments of the present invention. As such, thethree-dimensional image rendered by the present display device is lesslikely to suffer from the chromatic aberration result from the viewingangle. Also, the viewing distances under different viewing modes may bekept similar by using the present display device.

According to one embodiment of the present invention, the display devicecomprises a display panel and a parallax barrier, such as the parallaxbarrier 200 or 500 described hereinabove. The display panel is operableto render a two-dimensional image; whereas the parallax barrier (such asparallax barrier 200 or 500) is operable to transform thetwo-dimensional image rendered by the display panel into a parallaximage. The parallax image may provide a left-eye image and right-eyeimage to user's left and right eyes respectively, so that the user mayperceive a three-dimensional image.

In the present embodiment, the display panel may comprise a liquidcrystal display panel. The liquid crystal display panel may comprise,for example, a light source, a polarizer and a liquid crystal displayunit. One example of the light source is a backlight module; however,the present invention is not limited thereto.

According to the principles and spirits of the present invention, instill another aspect, the present invention is directed to a method forforming an autostereoscopic image. Briefly, the method includesoperating a parallax barrier (such as parallax barrier 200 or 500) totransform a two-dimensional image rendered by a display panel into aparallax image, wherein the parallax image may provide a left-eye imageand a right-eye image to a user's left and right eyes respectively, sothat the user's brain may perceive a three-dimensional image, asdescribed in FIG. 5A and FIG. 6D.

According to various embodiments of the present invention, the methodfor forming an autostereoscopic image is suitable for use in formingautostereoscopic image under a first mode and/or a second mode. As usedherein, the terms “first mode” and “second mode” generally refer to theviewing orientations of the display device, such as the portrait mode orthe landscape mode. For example, the display device can be rotatedrespect to a base of an electronic device by 90 degrees therebyswitching the display device from the portrait mode to the landscapemode.

FIG. 8 is a flow chart illustrating the steps of a method 800 forforming autostereoscopic images according to one embodiment of thepresent invention.

In step 802, a two-dimensional image is rendered by using display panel(such as the display panel 550 described hereinabove) of a displaydevice.

Also, the method 800 include a step of operating a parallax barrieraccording to the above-mentioned aspects/embodiments of the presentinvention (such as parallax barrier 200 or 500) to form a parallaxstructure.

Specifically, when the display device is operated under a first mode, areference voltage is applied to the second electrodes, the thirdelectrodes and the forth electrodes of the parallax barrier (such asparallax barrier 500), whereas a data voltage is applied to the firstelectrodes of the parallax barrier, so as to form a parallax structure(step 804).

Alternatively, when the display device is operated under a second mode,a reference voltage is applied to the first electrodes, the secondelectrodes and the forth electrodes of the parallax barrier, whereas adata voltage is applied to the third electrodes of the parallax barrier,so as to form a parallax structure (step 806).

Afterwards, in step 808, when the two-dimensional image rendered by thedisplay panel passes through either parallax structures formed in step804 or step 806, the two-dimensional image is transformed to a parallaximage by the parallax structure.

The parallax image is capable of providing a left-eye image and aright-eye image to a user's left and right eyes respectively so that theuser perceives a three-dimensional image.

Although the steps represented in FIG. 8 are presented in a specificorder in order to illustrate the method according to one embodiment ofthe present invention, the present invention is not limited thereto.Rather, the disclosed subject matter encompasses variations wherein thesteps and/or actions may be interchanged with one another withoutdeparting from the scope of the claims. In other words, unless aspecific order of steps or actions is required for proper operation ofthe process that is being described, the order and/or use of specificsteps and/or actions may be modified without departing from the scope ofthe claims. For example, in one embodiment, the step of forming aparallax structure (such as step 804 or step 806) may be carried outbefore the step of rendering the two-dimensional image (step 802).Alternatively, step 802 and step 804 (or step 806) may be carried out atthe same time.

It will be understood that the above description of embodiments is givenby way of example only and that various modifications may be made bythose with ordinary skill in the art. The above specification andexamples provide a complete description of the structure and use ofexemplary embodiments of the invention. Although various embodiments ofthe invention have been described above with a certain degree ofparticularity, or with reference to one or more individual embodiments,those with ordinary skill in the art could make numerous alterations tothe disclosed embodiments without departing from the spirit or scope ofthis invention.

What is claimed is:
 1. A parallax barrier, comprising: a firstsubstrate; a plurality of first electrodes disposed on the firstsubstrate along a first direction, wherein the first electrodes arestrip-shaped and electrically connected to one another; a plurality ofsecond electrodes disposed on the first substrate along the firstdirection, wherein the second electrodes are strip-shaped andelectrically connected to one another, and the first electrodes and thesecond electrodes are arranged alternately; a second substrate; aplurality of third electrodes disposed on the second substrate along asecond direction and electrically connected to one another, wherein eachof the third electrodes comprises at least one first portion beingstep-shaped; a plurality of forth electrodes disposed on the secondsubstrate along the second direction and electrically connected to oneanother, wherein each of the forth electrodes comprises at least onesecond portion being step-shaped, and the third electrodes and the forthelectrodes are arranged alternately; and a liquid crystal layer disposedbetween the first substrate and the second substrate.
 2. The parallaxbarrier of claim 1, wherein at least one of the first electrodes isdisposed between the two adjacent second electrodes.
 3. The parallaxbarrier of claim 1, wherein the first electrodes, the second electrodes,the third electrodes and the forth electrodes are made of a transparentconductive layer, respectively.
 4. The parallax barrier of claim 1,wherein at least one of the first electrodes comprises: a plurality oftransparent conductive patterns, the transparent conductive patternsbeing separated from one another; and at least one opaque bridgingpattern for bridging the transparent conductive patterns so that thetransparent conductive patterns are electrically connected to oneanother, wherein the at least one opaque bridging pattern is disposedabove a gap between the adjacent third electrode and the forthelectrode.
 5. The parallax barrier of claim 1, further comprising atleast one opaque bridging pattern, wherein the at least one opaquebridging pattern is disposed at an overlap between the first electrodeand a gap between the two adjacent third electrode and forth electrode.6. The parallax barrier of claim 1, wherein at least one of the thirdelectrodes comprises: a plurality of transparent conductive patterns,the transparent conductive patterns being separated from one another;and at least one opaque bridging pattern for bridging the transparentconductive patterns so that the transparent conductive patterns areelectrically connected to one another, wherein the at least one opaquebridging pattern is disposed above a gap between the adjacent firstelectrode and second electrode.
 7. The parallax barrier of claim 1,further comprising at least one opaque bridging pattern, wherein the atleast one opaque bridging pattern is disposed at an overlap between thethird electrode and a gap between the two adjacent first electrode andsecond electrode.
 8. The parallax barrier of claim 1, further comprisinga black matrix layer for shielding a plurality of gaps between the firstelectrodes and the second electrodes or between the third electrodes andthe forth electrodes.
 9. The parallax barrier of claim 1, wherein eachof the third electrodes further comprises a third portion, the thirdportion being step-shaped and mirroring the first portion.
 10. A displaydevice, comprising: a display panel, comprising a plurality of pixelsbeing arranged in a pixel array along a first direction and a seconddirection, wherein each of the pixels has a width of Wp along the firstdirection and a height of Hp along the second direction, and each of thepixels comprises 3 sub-pixels, wherein each of the sub-pixels has awidth of (Wp/3) along the first direction; a parallax barrier disposedat a side of the display panel, the parallax barrier comprising: a firstsubstrate; a plurality of first electrodes disposed on the firstsubstrate along the first direction, wherein the first electrodes arestrip-shaped and electrically connected to one another; a plurality ofsecond electrodes disposed on the first substrate along the firstdirection, wherein the second electrodes are strip-shaped andelectrically connected to one another, and the first electrodes and thesecond electrodes are arranged alternately; a second substrate; aplurality of third electrodes disposed on the second substrate andelectrically connected to one another, wherein each of the thirdelectrodes comprises at least one first portion, the first portioncomprises three first segments arranged along the second direction asstep-shaped, and a step difference between any two adjacent firstsegments is (Wp/3) or (2Wp/3); a plurality of forth electrodes disposedon the second substrate and electrically connected to one another,wherein each of the forth electrodes comprises at least one secondportion, the second portion comprises three second segments arrangedalong the second direction as step-shaped, a step difference between anytwo adjacent second segments is (Wp/3) or (2Wp/3), and the thirdelectrodes and the forth electrodes are arranged alternately; and aliquid crystal layer disposed between the first substrate and the secondsubstrate.
 11. The display device of claim 10, wherein each of theadjacent first electrodes and second electrodes have a gap therebetween.12. The display device of claim 10, wherein each of the adjacent thirdelectrodes and forth electrodes have a gap therebetween.
 13. The displaydevice of claim 10, wherein the first electrodes, the second electrodes,the third electrodes and the forth electrodes are made of a transparentconductive layer, respectively.
 14. The display device of claim 10,wherein at least one of the first electrodes comprises: a plurality oftransparent conductive patterns, the transparent conductive patternsbeing separated from one another; and at least one opaque bridgingpattern for bridging the transparent conductive patterns so that thetransparent conductive patterns are electrically connected to oneanother, wherein the at least one opaque bridging pattern is disposedabove a gap between the adjacent third electrode and the forthelectrode.
 15. The display device of claim 10, further comprising atleast one opaque bridging pattern, wherein the at least one opaquebridging pattern is disposed at an overlap between the first electrodeand a gap between the two adjacent third electrode and forth electrode.16. The display device of claim 10, wherein at least one of the thirdelectrodes comprises: a plurality of transparent conductive patterns,the transparent conductive patterns being separated from one another;and at least one opaque bridging pattern for bridging the transparentconductive patterns so that the transparent conductive patterns areelectrically connected to one another, wherein the at least one opaquebridging pattern is disposed above a gap between the adjacent firstelectrode and second electrode.
 17. The display device of claim 10,further comprising at least one opaque bridging pattern, wherein the atleast one opaque bridging pattern is disposed at an overlap between thethird electrode and a gap between the two adjacent first electrode andsecond electrode.
 18. The display device of claim 10, further comprisinga black matrix layer for shielding a plurality of gaps between the firstelectrodes and the second electrodes or shielding a plurality of gapsbetween the third electrodes and the forth electrodes.
 19. The displaydevice of claim 10, wherein each the third electrodes further comprisinga third portion mirroring the first portion, and the third portioncomprises three third segments arranged along the second direction asstep-shaped, and a step difference between any two adjacent thirdsegments is (Wp/3) or (2Wp/3).